0
$\begingroup$

Somebody help me visualizing current. What is it actually? Not just with mathematical relations but with something that we can visualize too.

$\endgroup$

3 Answers 3

1
$\begingroup$

Inside a wire, electrons are moving around randomly due to thermal excitation. When you apply a voltage difference between the ends of the wire, a current will start flowing. This means that due to electromagnetic forces, the electrons will move more in one direction than the other, effectively causing a wave of charge to flow through the wire. This is how DC current works. In an AC current, the flow of charge is constantly switching direction, effectively shaking the electrons back and forth with no total displacement. This is another way of transferring force through the use of moving electrons.

An intuitive understanding might come from thinking about it as water instead of electrons. Imagine that the wire is a pipe full of water. Applying a voltage difference is like putting more pressure on one side of the pipe than the other (like blowing into one end, or tipping the pipe). This will cause the water to flow through the pipe, causing a current, much like the current in a river. Please be aware that this is a visualization, not a perfect analogy.

Note that the speed of the current propagating through the wire is much faster than the speed of the individual electrons, much like how the speed of sound is faster than the speed of each air molecule.

$\endgroup$
2
  • $\begingroup$ Thanks Codename47 . I have one query; Does that mean current is transfer of energy or is current itself a form of energy. $\endgroup$ Mar 4, 2019 at 5:52
  • $\begingroup$ What current is is transfer of electric charge. What current is used for is transfer of energy. It's like a waterfall: what it consists of is falling water, what it does is translate potential energy from the top into kinetic energy at the bottom. This does not mean that the water is a type of energy, but rather that it "contains" energy in the form of gravitational potential energy and kinetic energy. $\endgroup$ Mar 4, 2019 at 10:01
1
$\begingroup$

Imagine cars on a road 25m long. Imagine all the cars are moving with the same velocity. Now, let us look at one car. Let us now imagine that this car gained its velocity not by its engine, but by a rope at the end of the road pulling the car forward with a motor on the rope. now, we know that the motor did work to pull the car at the velocity its currently in. Now, imagine those cars as electrons and the road as a wire. The work the rope and motor did to move the car is the potential difference or voltage.

$\endgroup$
0
$\begingroup$

Current is the flow of electrons with specific direction . The direction is determined by the applied electric field . Current is not how much distance a electron move in a timespan , this is drift speed.It is the amount of the charge that is in one point of a closed circuit at any second.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.